The invention relates to the field of generator or alternator cooling systems and more particularly to cooling systems utilizing a cooling fluid within the stator itself.
In the prior art, specifically represented by Montsinger U.S. Pat. No. 2,036,068, Theodore U.S. Pat. No. 3,670,276 and the British Patent No. 578,869, spherical insulating balls have been used in transformers and the like in order to reduce the amount of more expensive insulating fluid, usually an oil with a high dielectric coefficient, required for insulation. In addition, the prior art including Fechheimer U.S. Pat. No. 2,285,960, Cametti et al. U.S. Pat. No. 2,887,061, Seidner U.S. Pat. No. 2,975,309 and Smith U.S. Pat. No. 3,743,867, teaches the technique of circulating a cooling oil through the stator structure of a generator.
One of the major problems in designing alternators of high power output with a minimum of weight, for use in aircraft power generating systems as an example, is the provision for efficient cooling of the stator wires. To solve this problem, one approach has been to allow the coolant to flow along the stator wires in the stator slots. However, it is highly desirable to provide for even distribution of the cooling fluid over the various components of the stator since by ensuring uniform oil flow over the various components, the maximum current through the stator wires can be achieved with a minimum of structural and hence weight requirements.